There is an increasing need in the electronics industry for test and measurement instruments, such as oscilloscopes, logic analyzers and the like, to measure electrical signals that are galvanically isolated and contain higher frequency content. One way to measure electrical signals that are galvanically isolated and have higher frequency content is to use an electro-optic probe.
Traditionally, the gain and sensitivity of an electro-optic probe is adjusted by controlling a variable gain amplifier of an optical-to-electrical converter. Controlling a variable gain of the optical-to-electrical converter results in higher sensitivity but a reduction in the overall bandwidth and frequency response of the test and measurement system. That is, gain and/or sensitivity for the test and measurement system is adjusted at the optical-to-electrical converter after a light beam has been emitted and a measurement has been taken at a device under test (DUT). Typically, the electro-optic probe also requires a user to develop an application specific integrated circuit (ASIC) to achieve the desired parameters of the electro-optic probe. In order to achieve the ability to have an adjustable gain, the dynamic range, noise, frequency and bandwidth response and overall system complexity must be compromised.